Asthma, Ozone, and AQI

While we talk a lot about indoor air quality, the health benefits that come from breathing clean air inside can be undone by breathing low quality air outdoors.

Asthma, Ozone, AQI Explained

The biggest contributor to air quality is ozone. Ground-level ozone that we breathe mostly comes from reactions of man-made VOCs (volatile organic compounds), most commonly from chemical plants, gas pumps, and print shops.

When you inhale ozone, it reacts with molecules in your lungs and can cause coughing, irritation, chest tightness, shortness of breath, and even pain and burning sensations. Breathing in air heavy with ozone can decrease lung function and inflame the airways.

Although it may seem logical to think that the areas with the highest ozone concentrations would be major cities such as Houston or New York, ozone can also form in smaller cities and be transported hundreds of miles downwind to rural areas as well. Ozone usually starts to build up in the afternoon due to the intense sunlight. So many places experience the worst air quality in the afternoon and evening.

Higher daily ozone concentrations are associated with increased asthma attacks, hospital admissions, and even death, especially in older adults and during the warmer seasons.

For people with asthma, higher ozone concentrations can affect you in several ways, making asthma symptoms worse and increasing your sensitivity to asthma triggers. The amount of exposure and how much air you breathe in also matters. Even on days when the air quality is better, ozone in the air can affect you significantly more than someone without asthma. For instance, if you perform a strenuous activity, even at low concentrations, you may find it harder to breathe and have more asthmatic symptoms.

One thing scientists are still unsure about is the long-term health effects of breathing in ozone. The inflammation and airway reactivity caused by ozone exposure can make asthma worse and increase the chance of an asthma attack. And the short-term effects alone can be devastating, costing time, money, and even in some cases, lives.

Most health care providers and public health organizations recommend that people with asthma, especially children and the elderly, reduce the time spent outdoors or cancel vigorous outdoor activities during times when ozone levels are high, which can vary by location.

Unfortunately, because of the demands of modern society, air quality is an issue across the globe. Just this past Sunday, Beijing asked its citizens to stay indoors during a spike in smog, which was accompanied by a 30% increase in hospital admissions. Residents and schools were forced to cancel all outdoor activities.

The EPA website AirNow provides up-to-date information about the AQI, or air quality index, in areas across the United States. When the air quality levels are orange or higher, people with asthma may be severely affected. When the AQI is extremely unhealthy, the site calls for an action day on which all residents should stay indoors and reduce exposure to outdoor air. Checking the AQI daily can help you keep your family safe, keep asthma in control, and reduce the health complications that may arise from breathing ozone.